I have two problems with opera (even though I'm using an earlier version of opera now), is that some of the 'corporate' web site which I need to use, require an early version of netscape, which opera doesn't proppery render. Also, requring to buy a new version every year at 35 bucks a pop gets expensive. Plus, for a long time, it didn't have support for imap protocol which I use heavily at work. (begining to get off topic here...)

Aside from some websites who dynamically alter the DOM of the page Opera does most things correctly (and some things even better than IE, IMAP is supported and there's no need to fork over $35 if you use the adware version :).